Polyetheresteramides have attracted attention recently as new materials for elastomers. Particularly, they have excellent weight reduction, low-temperature properties, chemical resistance, oil resistance, sound-damping qualities and moldability. The demand of them is expected in the production of automobile hoses, tubes, rubber for wipers and soles of sport shoes as well as in other fields wherein a strict hygienic control is required, such as food and medical appliances.
The polyetheresteramides have defects that they are colored due to a decomposition reaction in the course of the polymerization and that their mechanical and physical properties are deteriorated during the use at a high temperature, while polyesteramides have a defect of poor water resistance.
After intensive investigations made for the purpose of producing colorless polyamide elastomers having excellent weight reduction, low-temperature properties, chemical resistance, oil resistance, sound-damping qualities, moldability, heat resistance and water resistance, the inventors have found that the above-mentioned polyamide elastomers can be obtained by reacting (1) at least one polyamide-forming compound selected from the group consisting of amino carboxylic acids, lactams and nylon salts, (2) a dicarboxylic acid and (3) a polycaprolactonediol. The present invention has been completed on the basis of this finding.